What Transfer case should I have?

My son just bought a 93 Cherokee Sport with a 4.0L in it. The guy that he bought it from said that the t-case was bad so he had it replaced but that the wrong case was installed. The case that is in it now is a NP231j and you can not hook it up electrically because the plus are differant. The t-case handle has four positions (2H, 4H, N and 4L). So the big question is - What is the right t-case that belongs in this Cherokee?

my 94 sport came with a 231 although the 242 was an option. From what I've heard, a 242(selec-trac) will not just bolt right up and work. The 242 should be longer and require a shorter driveshaft. If anything else, maybe the dealer could run your VIN and check it.

Plugs?

There's nothing electrical about the transfer case.

231J is a Jeep Command-Trac transfer case, and that's what was standard in your XJ. Here's what I suspect:

The 231 was introduced in 1987 or 1988 for use with the 4.0L engine. From 87 thru 90 the XJ used a mechanical speedometer with a standard cable drive. In 1991 they went to an electronic speedometer, so there is speedo cable, just wires.

Your 93 has the electronic speedo. I'm going to guess that you may have a transfer case for an older year. If that's the case, you should be able to remove the speedo drive module from the transfer case and replace it with the module for a '93, plug in the speedo wire, and drive.

It may be that the late-models used a different plug on the speedo sensor, in which case the same scenario would apply in reverse -- the plug on your t-case may be for a newer model. If the speedo output is all electrical (no place to attach a physical cable), you might be able to make up an adapter harness with two aftermarket connectors to join the two mis-matched plugs together. If possible, can you post pics of the two connectors, and tell us the wire colors?